Window fan



FIG. 1 is a front and right side perspective view of a window fan showing our new design;

FIG. 2 is an enlarged right side elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a rear elevation view thereof.

The left side and bottom view are mirror images of the right side and top view with the exception of the control switch. 

The ornamental design for a window fan, as shown and described. 